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Flight Reliability

UA 4878 · United Airlines

MOB → Houston (MOB–IAH)99% of its flights flew this route. The rest (ORF–IAD) are included in these numbers.

94
Nerd Approved
WanderNerd Reliability Score
88%
Arrive within 15 minutes
0 min
Average arrival delay
0.5%
Cancelled
17 min early
Median arrival delay

Based on 364 historical flights. Data through May 2026.

What the data says

12–3 PM has a slight edge.

Departures between 12–3 PM arrived on time 92% of the time, against 88% between 9 AM–12 PM.

Friday is doing you no favors.

UA 4878 arrived on time 92% of the time on Mondays and just 77% on Fridays. That gap is worth planning around.

Better than the United Airlines network average.

UA 4878 arrived on time 88% of the time, versus 79% across the United Airlines network.

Slipping a little lately.

UA 4878 arrived on time 86% of the time over the last three months in the data, compared with 92% in the three months before that.

The breakdown

On-time by weekday
  • Mon92%(52 flights)
  • Tue90%(51 flights)
  • Wed92%(52 flights)
  • Thu90%(51 flights)
  • Fri77%(52 flights)
  • Sat89%(52 flights)
  • Sun89%(52 flights)
On-time by departure window
  • 9 AM–12 PM88%(325 flights)
  • 12–3 PM92%(37 flights)
On-time trend by month
84%
May

Jun 69% → May 84% on time

On-time arrival percentage by month
MonthOn-time percentageFlights
June 202569%29
July 202584%31
August 202587%31
September 202597%30
October 202597%31
November 202593%30
December 202584%31
January 202693%30
February 2026100%28
March 202683%30
April 202690%30
May 202684%31
Departures on time
89%
Diverted
0%
Flights flown
362
Months covered
12

Same route, other flights

Keep nerding

Based on 364 historical flights, because apparently we checked. Historical flight data: U.S. Bureau of Transportation Statistics, June 2025 – May 2026. Data through May 2026. How we calculate this.